/* * Copyright (C) 2011 Instituto Nokia de Tecnologia * * Authors: * Lauro Ramos Venancio <lauro.venancio@openbossa.org> * Aloisio Almeida Jr <aloisio.almeida@openbossa.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the * Free Software Foundation, Inc., * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__ #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/nfc.h> #include <net/genetlink.h> #include "nfc.h" #define VERSION "0.1" #define NFC_CHECK_PRES_FREQ_MS 2000 int nfc_devlist_generation; DEFINE_MUTEX(nfc_devlist_mutex); /* NFC device ID bitmap */ static DEFINE_IDA(nfc_index_ida); /** * nfc_dev_up - turn on the NFC device * * @dev: The nfc device to be turned on * * The device remains up until the nfc_dev_down function is called. */ int nfc_dev_up(struct nfc_dev *dev) { int rc = 0; pr_debug("dev_name=%s\n", dev_name(&dev->dev)); device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; goto error; } if (dev->dev_up) { rc = -EALREADY; goto error; } if (dev->ops->dev_up) rc = dev->ops->dev_up(dev); if (!rc) dev->dev_up = true; error: device_unlock(&dev->dev); return rc; } /** * nfc_dev_down - turn off the NFC device * * @dev: The nfc device to be turned off */ int nfc_dev_down(struct nfc_dev *dev) { int rc = 0; pr_debug("dev_name=%s\n", dev_name(&dev->dev)); device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; goto error; } if (!dev->dev_up) { rc = -EALREADY; goto error; } if (dev->polling || dev->active_target) { rc = -EBUSY; goto error; } if (dev->ops->dev_down) dev->ops->dev_down(dev); dev->dev_up = false; error: device_unlock(&dev->dev); return rc; } /** * nfc_start_poll - start polling for nfc targets * * @dev: The nfc device that must start polling * @protocols: bitset of nfc protocols that must be used for polling * * The device remains polling for targets until a target is found or * the nfc_stop_poll function is called. */ int nfc_start_poll(struct nfc_dev *dev, u32 im_protocols, u32 tm_protocols) { int rc; pr_debug("dev_name %s initiator protocols 0x%x target protocols 0x%x\n", dev_name(&dev->dev), im_protocols, tm_protocols); if (!im_protocols && !tm_protocols) return -EINVAL; device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; goto error; } if (dev->polling) { rc = -EBUSY; goto error; } rc = dev->ops->start_poll(dev, im_protocols, tm_protocols); if (!rc) { dev->polling = true; dev->rf_mode = NFC_RF_NONE; } error: device_unlock(&dev->dev); return rc; } /** * nfc_stop_poll - stop polling for nfc targets * * @dev: The nfc device that must stop polling */ int nfc_stop_poll(struct nfc_dev *dev) { int rc = 0; pr_debug("dev_name=%s\n", dev_name(&dev->dev)); device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; goto error; } if (!dev->polling) { rc = -EINVAL; goto error; } dev->ops->stop_poll(dev); dev->polling = false; dev->rf_mode = NFC_RF_NONE; error: device_unlock(&dev->dev); return rc; } static struct nfc_target *nfc_find_target(struct nfc_dev *dev, u32 target_idx) { int i; if (dev->n_targets == 0) return NULL; for (i = 0; i < dev->n_targets; i++) { if (dev->targets[i].idx == target_idx) return &dev->targets[i]; } return NULL; } int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode) { int rc = 0; u8 *gb; size_t gb_len; struct nfc_target *target; pr_debug("dev_name=%s comm %d\n", dev_name(&dev->dev), comm_mode); if (!dev->ops->dep_link_up) return -EOPNOTSUPP; device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; goto error; } if (dev->dep_link_up == true) { rc = -EALREADY; goto error; } gb = nfc_llcp_general_bytes(dev, &gb_len); if (gb_len > NFC_MAX_GT_LEN) { rc = -EINVAL; goto error; } target = nfc_find_target(dev, target_index); if (target == NULL) { rc = -ENOTCONN; goto error; } rc = dev->ops->dep_link_up(dev, target, comm_mode, gb, gb_len); if (!rc) { dev->active_target = target; dev->rf_mode = NFC_RF_INITIATOR; } error: device_unlock(&dev->dev); return rc; } int nfc_dep_link_down(struct nfc_dev *dev) { int rc = 0; pr_debug("dev_name=%s\n", dev_name(&dev->dev)); if (!dev->ops->dep_link_down) return -EOPNOTSUPP; device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; goto error; } if (dev->dep_link_up == false) { rc = -EALREADY; goto error; } rc = dev->ops->dep_link_down(dev); if (!rc) { dev->dep_link_up = false; dev->active_target = NULL; dev->rf_mode = NFC_RF_NONE; nfc_llcp_mac_is_down(dev); nfc_genl_dep_link_down_event(dev); } error: device_unlock(&dev->dev); return rc; } int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx, u8 comm_mode, u8 rf_mode) { dev->dep_link_up = true; nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode); return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode); } EXPORT_SYMBOL(nfc_dep_link_is_up); /** * nfc_activate_target - prepare the target for data exchange * * @dev: The nfc device that found the target * @target_idx: index of the target that must be activated * @protocol: nfc protocol that will be used for data exchange */ int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol) { int rc; struct nfc_target *target; pr_debug("dev_name=%s target_idx=%u protocol=%u\n", dev_name(&dev->dev), target_idx, protocol); device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; goto error; } if (dev->active_target) { rc = -EBUSY; goto error; } target = nfc_find_target(dev, target_idx); if (target == NULL) { rc = -ENOTCONN; goto error; } rc = dev->ops->activate_target(dev, target, protocol); if (!rc) { dev->active_target = target; dev->rf_mode = NFC_RF_INITIATOR; if (dev->ops->check_presence) mod_timer(&dev->check_pres_timer, jiffies + msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS)); } error: device_unlock(&dev->dev); return rc; } /** * nfc_deactivate_target - deactivate a nfc target * * @dev: The nfc device that found the target * @target_idx: index of the target that must be deactivated */ int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx) { int rc = 0; pr_debug("dev_name=%s target_idx=%u\n", dev_name(&dev->dev), target_idx); device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; goto error; } if (dev->active_target == NULL) { rc = -ENOTCONN; goto error; } if (dev->active_target->idx != target_idx) { rc = -ENOTCONN; goto error; } if (dev->ops->check_presence) del_timer_sync(&dev->check_pres_timer); dev->ops->deactivate_target(dev, dev->active_target); dev->active_target = NULL; error: device_unlock(&dev->dev); return rc; } /** * nfc_data_exchange - transceive data * * @dev: The nfc device that found the target * @target_idx: index of the target * @skb: data to be sent * @cb: callback called when the response is received * @cb_context: parameter for the callback function * * The user must wait for the callback before calling this function again. */ int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb, data_exchange_cb_t cb, void *cb_context) { int rc; pr_debug("dev_name=%s target_idx=%u skb->len=%u\n", dev_name(&dev->dev), target_idx, skb->len); device_lock(&dev->dev); if (!device_is_registered(&dev->dev)) { rc = -ENODEV; kfree_skb(skb); goto error; } if (dev->rf_mode == NFC_RF_INITIATOR && dev->active_target != NULL) { if (dev->active_target->idx != target_idx) { rc = -EADDRNOTAVAIL; kfree_skb(skb); goto error; } if (dev->ops->check_presence) del_timer_sync(&dev->check_pres_timer); rc = dev->ops->im_transceive(dev, dev->active_target, skb, cb, cb_context); if (!rc && dev->ops->check_presence) mod_timer(&dev->check_pres_timer, jiffies + msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS)); } else if (dev->rf_mode == NFC_RF_TARGET && dev->ops->tm_send != NULL) { rc = dev->ops->tm_send(dev, skb); } else { rc = -ENOTCONN; kfree_skb(skb); goto error; } error: device_unlock(&dev->dev); return rc; } int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len) { pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len); if (gb_len > NFC_MAX_GT_LEN) return -EINVAL; return nfc_llcp_set_remote_gb(dev, gb, gb_len); } EXPORT_SYMBOL(nfc_set_remote_general_bytes); u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, size_t *gb_len) { pr_debug("dev_name=%s\n", dev_name(&dev->dev)); return nfc_llcp_general_bytes(dev, gb_len); } EXPORT_SYMBOL(nfc_get_local_general_bytes); int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb) { /* Only LLCP target mode for now */ if (dev->dep_link_up == false) { kfree_skb(skb); return -ENOLINK; } return nfc_llcp_data_received(dev, skb); } EXPORT_SYMBOL(nfc_tm_data_received); int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode, u8 *gb, size_t gb_len) { int rc; device_lock(&dev->dev); dev->polling = false; if (gb != NULL) { rc = nfc_set_remote_general_bytes(dev, gb, gb_len); if (rc < 0) goto out; } dev->rf_mode = NFC_RF_TARGET; if (protocol == NFC_PROTO_NFC_DEP_MASK) nfc_dep_link_is_up(dev, 0, comm_mode, NFC_RF_TARGET); rc = nfc_genl_tm_activated(dev, protocol); out: device_unlock(&dev->dev); return rc; } EXPORT_SYMBOL(nfc_tm_activated); int nfc_tm_deactivated(struct nfc_dev *dev) { dev->dep_link_up = false; dev->rf_mode = NFC_RF_NONE; return nfc_genl_tm_deactivated(dev); } EXPORT_SYMBOL(nfc_tm_deactivated); /** * nfc_alloc_send_skb - allocate a skb for data exchange responses * * @size: size to allocate * @gfp: gfp flags */ struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk, unsigned int flags, unsigned int size, unsigned int *err) { struct sk_buff *skb; unsigned int total_size; total_size = size + dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err); if (skb) skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); return skb; } /** * nfc_alloc_recv_skb - allocate a skb for data exchange responses * * @size: size to allocate * @gfp: gfp flags */ struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp) { struct sk_buff *skb; unsigned int total_size; total_size = size + 1; skb = alloc_skb(total_size, gfp); if (skb) skb_reserve(skb, 1); return skb; } EXPORT_SYMBOL(nfc_alloc_recv_skb); /** * nfc_targets_found - inform that targets were found * * @dev: The nfc device that found the targets * @targets: array of nfc targets found * @ntargets: targets array size * * The device driver must call this function when one or many nfc targets * are found. After calling this function, the device driver must stop * polling for targets. * NOTE: This function can be called with targets=NULL and n_targets=0 to * notify a driver error, meaning that the polling operation cannot complete. * IMPORTANT: this function must not be called from an atomic context. * In addition, it must also not be called from a context that would prevent * the NFC Core to call other nfc ops entry point concurrently. */ int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets, int n_targets) { int i; pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets); for (i = 0; i < n_targets; i++) targets[i].idx = dev->target_next_idx++; device_lock(&dev->dev); if (dev->polling == false) { device_unlock(&dev->dev); return 0; } dev->polling = false; dev->targets_generation++; kfree(dev->targets); dev->targets = NULL; if (targets) { dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target), GFP_ATOMIC); if (!dev->targets) { dev->n_targets = 0; device_unlock(&dev->dev); return -ENOMEM; } } dev->n_targets = n_targets; device_unlock(&dev->dev); nfc_genl_targets_found(dev); return 0; } EXPORT_SYMBOL(nfc_targets_found); /** * nfc_target_lost - inform that an activated target went out of field * * @dev: The nfc device that had the activated target in field * @target_idx: the nfc index of the target * * The device driver must call this function when the activated target * goes out of the field. * IMPORTANT: this function must not be called from an atomic context. * In addition, it must also not be called from a context that would prevent * the NFC Core to call other nfc ops entry point concurrently. */ int nfc_target_lost(struct nfc_dev *dev, u32 target_idx) { struct nfc_target *tg; int i; pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx); device_lock(&dev->dev); for (i = 0; i < dev->n_targets; i++) { tg = &dev->targets[i]; if (tg->idx == target_idx) break; } if (i == dev->n_targets) { device_unlock(&dev->dev); return -EINVAL; } dev->targets_generation++; dev->n_targets--; dev->active_target = NULL; if (dev->n_targets) { memcpy(&dev->targets[i], &dev->targets[i + 1], (dev->n_targets - i) * sizeof(struct nfc_target)); } else { kfree(dev->targets); dev->targets = NULL; } device_unlock(&dev->dev); nfc_genl_target_lost(dev, target_idx); return 0; } EXPORT_SYMBOL(nfc_target_lost); inline void nfc_driver_failure(struct nfc_dev *dev, int err) { nfc_targets_found(dev, NULL, 0); } EXPORT_SYMBOL(nfc_driver_failure); static void nfc_release(struct device *d) { struct nfc_dev *dev = to_nfc_dev(d); pr_debug("dev_name=%s\n", dev_name(&dev->dev)); if (dev->ops->check_presence) { del_timer_sync(&dev->check_pres_timer); cancel_work_sync(&dev->check_pres_work); } nfc_genl_data_exit(&dev->genl_data); kfree(dev->targets); kfree(dev); } static void nfc_check_pres_work(struct work_struct *work) { struct nfc_dev *dev = container_of(work, struct nfc_dev, check_pres_work); int rc; device_lock(&dev->dev); if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) { rc = dev->ops->check_presence(dev, dev->active_target); if (rc == -EOPNOTSUPP) goto exit; if (!rc) { mod_timer(&dev->check_pres_timer, jiffies + msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS)); } else { u32 active_target_idx = dev->active_target->idx; device_unlock(&dev->dev); nfc_target_lost(dev, active_target_idx); return; } } exit: device_unlock(&dev->dev); } static void nfc_check_pres_timeout(unsigned long data) { struct nfc_dev *dev = (struct nfc_dev *)data; schedule_work(&dev->check_pres_work); } struct class nfc_class = { .name = "nfc", .dev_release = nfc_release, }; EXPORT_SYMBOL(nfc_class); static int match_idx(struct device *d, void *data) { struct nfc_dev *dev = to_nfc_dev(d); unsigned int *idx = data; return dev->idx == *idx; } struct nfc_dev *nfc_get_device(unsigned int idx) { struct device *d; d = class_find_device(&nfc_class, NULL, &idx, match_idx); if (!d) return NULL; return to_nfc_dev(d); } /** * nfc_allocate_device - allocate a new nfc device * * @ops: device operations * @supported_protocols: NFC protocols supported by the device */ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops, u32 supported_protocols, int tx_headroom, int tx_tailroom) { struct nfc_dev *dev; if (!ops->start_poll || !ops->stop_poll || !ops->activate_target || !ops->deactivate_target || !ops->im_transceive) return NULL; if (!supported_protocols) return NULL; dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL); if (!dev) return NULL; dev->ops = ops; dev->supported_protocols = supported_protocols; dev->tx_headroom = tx_headroom; dev->tx_tailroom = tx_tailroom; nfc_genl_data_init(&dev->genl_data); dev->rf_mode = NFC_RF_NONE; /* first generation must not be 0 */ dev->targets_generation = 1; if (ops->check_presence) { init_timer(&dev->check_pres_timer); dev->check_pres_timer.data = (unsigned long)dev; dev->check_pres_timer.function = nfc_check_pres_timeout; INIT_WORK(&dev->check_pres_work, nfc_check_pres_work); } return dev; } EXPORT_SYMBOL(nfc_allocate_device); /** * nfc_register_device - register a nfc device in the nfc subsystem * * @dev: The nfc device to register */ int nfc_register_device(struct nfc_dev *dev) { int rc; pr_debug("dev_name=%s\n", dev_name(&dev->dev)); dev->idx = ida_simple_get(&nfc_index_ida, 0, 0, GFP_KERNEL); if (dev->idx < 0) return dev->idx; dev->dev.class = &nfc_class; dev_set_name(&dev->dev, "nfc%d", dev->idx); device_initialize(&dev->dev); mutex_lock(&nfc_devlist_mutex); nfc_devlist_generation++; rc = device_add(&dev->dev); mutex_unlock(&nfc_devlist_mutex); if (rc < 0) return rc; rc = nfc_llcp_register_device(dev); if (rc) pr_err("Could not register llcp device\n"); rc = nfc_genl_device_added(dev); if (rc) pr_debug("The userspace won't be notified that the device %s was added\n", dev_name(&dev->dev)); return 0; } EXPORT_SYMBOL(nfc_register_device); /** * nfc_unregister_device - unregister a nfc device in the nfc subsystem * * @dev: The nfc device to unregister */ void nfc_unregister_device(struct nfc_dev *dev) { int rc, id; pr_debug("dev_name=%s\n", dev_name(&dev->dev)); id = dev->idx; mutex_lock(&nfc_devlist_mutex); nfc_devlist_generation++; /* lock to avoid unregistering a device while an operation is in progress */ device_lock(&dev->dev); device_del(&dev->dev); device_unlock(&dev->dev); mutex_unlock(&nfc_devlist_mutex); nfc_llcp_unregister_device(dev); rc = nfc_genl_device_removed(dev); if (rc) pr_debug("The userspace won't be notified that the device %s was removed\n", dev_name(&dev->dev)); ida_simple_remove(&nfc_index_ida, id); } EXPORT_SYMBOL(nfc_unregister_device); static int __init nfc_init(void) { int rc; pr_info("NFC Core ver %s\n", VERSION); rc = class_register(&nfc_class); if (rc) return rc; rc = nfc_genl_init(); if (rc) goto err_genl; /* the first generation must not be 0 */ nfc_devlist_generation = 1; rc = rawsock_init(); if (rc) goto err_rawsock; rc = nfc_llcp_init(); if (rc) goto err_llcp_sock; rc = af_nfc_init(); if (rc) goto err_af_nfc; return 0; err_af_nfc: nfc_llcp_exit(); err_llcp_sock: rawsock_exit(); err_rawsock: nfc_genl_exit(); err_genl: class_unregister(&nfc_class); return rc; } static void __exit nfc_exit(void) { af_nfc_exit(); nfc_llcp_exit(); rawsock_exit(); nfc_genl_exit(); class_unregister(&nfc_class); } subsys_initcall(nfc_init); module_exit(nfc_exit); MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>"); MODULE_DESCRIPTION("NFC Core ver " VERSION); MODULE_VERSION(VERSION); MODULE_LICENSE("GPL"); MODULE_ALIAS_NETPROTO(PF_NFC); MODULE_ALIAS_GENL_FAMILY(NFC_GENL_NAME);